Mechanical

Question 1

Conduction?

Answer 1

Transfer of heat from one body to another

Question 2

Convection

Answer 2

Body gives off heat to surrounding cooler air : induced by differences in temperature

Question 3

Radiation

Answer 3

Heat emitted by warm body transmitted through space - absorbed by cooler body

Question 4

What are the 4 factors of comfort ?

Answer 4

-MRT mean radiant temperature
(40% more effect than air temp)
-relative humidity
-air temp + air motion

Question 5

Psychrometer

Answer 5

Question 6

Adiabatic heating

Answer 6

Rise in temperature occurs without addition or removal of heat

Question 7

What is the heating load?

Answer 7

BTU/hr

Hourly rate of heating loss / hour
-convection, radiation, conduction + infiltration of cool air

Question 8

Biomass; pros + cons

Answer 8

-burning organic matter
-some consider carbon neutral, as they capture as much carbon as released
-required more energy to convert than it produces; energy negative

Question 9

Solar power energy

Answer 9

Require storage for
When sun no shine-o

Question 10

Solar power cons :

Answer 10

Best sites are very remote form where energy is consumed

Question 11

Hydrogen

Answer 11

Low energy for volume, high energy for
Weight: storage issues

Question 12

Heat pump

Answer 12

-electrically powered
-heat and cooling
-Condenser and evaporator
-most efficient moderate climates
-

Question 13

Absorption refrigeration

Answer 13

-uses heat source (propane)
-saline solutions draws water from evaporator

Question 14

CAV

Answer 14

• Constant air volume

Question 15

VAV

Answer 15

Variable air volume

Question 16

Hot water in plastic pipes , which kind ?

Answer 16

PB (poly butaline) and CPVC only

Question 17

How do septic tanks work ?

Answer 17

-water tight tank
-separates organic matter with decomposes anaerobic bacteria
-clarifies liquid
-when 70% purifies ; weeping field